LONDON (Reuters Health) May 17 - Treatment with interferon beta-1a appears to slow the rate of multiple sclerosis (MS) progression when begun within 3 months of an initial neurologic episode, according to study data. However, an editorialist questions whether the results are of any significance for clinical practice.
Subjects in the study had experienced a neurologic episode suggestive of MS within the previous 3 months, had at least one abnormality according to neurologic examination and had a positive brain MRI scan.
As reported in the May 19th issue of The Lancet, Dr. Giancarlo Comi, of the University of Milan, Italy, and associates randomly assigned 154 subjects to treatment with interferon beta-1a, 22 µg subcutaneously once a week, and 154 to placebo.
Thirty-four percent of patients in the treatment arm converted to clinically definite MS within 2 years, compared with 45% of placebo-treated subjects. It took significantly longer for those treated with interferon beta-1a to experience a relapse.
Interferon-treated subjects developed significantly fewer new T2 lesions than did those treated with placebo, though there was no difference between groups for T1 active lesions. Thus, the investigators write, "interferon beta-1a did not stop the disease activity in the vast majority." The treatment also had no effect on disability over the 2-year study period.
Dr. George Ebers, of the University of Oxford, expresses skepticism about the study results in an accompanying editorial. He points out that there is as yet no evidence to support any impact of interferons on the progression of MS apart from their possible effect on relapse. He notes that similar delays in second exacerbations have been seen with the use of solumedrol during initial episodes of optic neuritis.
"The financial implications are enormous," he writes, given that 6 years of treatment are required to suppress a single relapse, based on data in this study. He adds, "Pharmaco-economic roads converge on the same question — do interferons influence the long-term course of the disease?" He concludes that uncertainty on this question "seems destined to persist for an uncomfortably long time."
"What is important is just to slow progression and maintain the quality of life of people with MS for as long as possible," Dr. Patricia O'Looney, director of Research Programs for the National Multiple Sclerosis Society, in New York, told Reuters Health. "Preventing a second attack could have long-term clinical benefit, although we don't know that yet for sure."
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